Hmm, did a quick google and it looks like it's silica sand. As long as the sand isn't pretreated in any way, it's fine for use IMO. Some don't like using silica sand becaues it supposedly can leach into the water and cause diatom problems and such...but glass is almost all silica and it doesn't cause problems. There just isn't enough evidence to back up that theory in my opinion.
Bonsal seems to be an Oldcastle company, the same people that made Southdown, the heavily touted sand. Play sand is great to use, though if you can find a sand equally cheap that is aragonite based, it will be better for your water, helping to keep it buffered.
To test for aragonite based sand, take some vinegar in a dropper bottle with you to the store. Drop some vinegar on the sand. If it bubbles/fizzes, it's aragonite based and thus will help buffer your water. Doesn't mean you can't use non-aragonite based sand, just that aragonite sand is, IMO, better.
I believe one of the more popular brands is Kolorscape.